Whether the Fifth and Fourteenth Amendments forbid judges (or prosecutors) from instructing (or inviting) the jury to take into account a non-testifying criminal defendant's courtroom demeanor as a basis for finding guilt

QUESTION PRESENTED In a criminal trial, “[d]ue process means a jury capable and willing to decide the case solely on the evidence before it, and a trial judge ever watchful to prevent prejudicial occurrences.” Smith v. Phillips, 455 U.S. 209, 217 (1982). Thus, a jury may not consider facts outside the official record in determining a criminal defendant’s guilt or innocence. See, e.g., Taylor v. Kentucky, 436 U.S. 478, 485 (1978). The lower court’s decision in this case offends that basic maxim. After the case was submitted to the jury in proceedings below, the jury foreman posed the following question to the trial judge: Can we take the defendants[’] body language into consideration? As evidence? Over petitioner’s repeated objections, but in compliance with settled Massachusetts law on the topic, the judge answered this way: While not evidence, the jury is entitled to consider any observations you made of the defendants’ demeanor during the trial. The lower courts are intractably split on the permissibility under the Federal Constitution of such an instruction. The question presented is whether the Fifth and Fourteenth Amendments forbid judges (or prosecutors) from instructing (or inviting) the jury to take into account a non-testifying criminal defendant’s courtroom demeanor as a basis for finding guilt. ii STATEMENT OF